Outlook on Aluminium Scrap Processing
According to the most accurate statistics available, about 1/3 of global production of aluminium comes from the reclamation of Aluminium scraps. It is equally well-known that the “resurrection” of aluminium scraps into secondary Aluminium requires approximately 95% lesser energy when compared with Aluminium produced starting from Al2O3.
For such reason, Aluminium scrap, in general, is somehow considered as “the bank of energy” which includes, more than forty (40) different typologies, as per the classification of Institute of Scrap Recycling Industries (ISRI).
Just to name some of them
- Sheets and Foils
- Used Beverage Cans [UBCs]
- Wires and Cables
- Pistons and Motors Castings
- Extruded Profiles
- Borings and Turnings
- Dross, Skimming and Similar.
Depending on the type of scrap it will be subjected to various pre-treatment operations that go from crushing to drying from decoating to balling etc., in order to be suitable for the smelting and alloying operations. In many cases the smelting occurs under a layer of salt (NaCl/KCl) in order to prevent oxidation. The resulting slag represents a waste by-product that must undergo through a dedicated recovery system.
The Engitec
STE Process
According to the most accurate statistics available, about 1/3 of global production of aluminium comes from the reclamation of Aluminium scraps. It is equally well-known that the “resurrection” of aluminium scraps into secondary Aluminium requires approximately 95% lesser energy when compared with Aluminium produced starting from Al2O3.
For such reason, Aluminium scrap, in general, is somehow considered as “the bank of energy” which includes, more than forty (40) different typologies, as per the classification of Institute of Scrap Recycling Industries (ISRI).
Just to name some of them:
The composition of the slag and the aluminium compounds contained in it can heavily address the process design. Engitec has developed a process, based on hydrometallurgy, for the treatment of this slag that has been called STE (standing for Slag Treatment Engitec).
The Engitec proprietary technology for the secondary aluminum industry is the STE process is suitable for large or for small productions and can be installed directly at the aluminum recyclers’ site.
The STE process allows the recovery of both residual aluminum and of the salt fractions, which is re-used in the smelting process. The fine clean oxides in the slag are recovered for use in other industrial applications such as cement manufacturing.
All polluting gases generated during the aluminum salt slag leaching are combusted and the heat generated is used for water evaporation and salt crystallization. No liquid effluents are released from the plant and the gaseous emissions are kept within regulatory limits.
As of now, Engitec has sold and commissioned seven STE complete Plants of various capacity in Europe and Canada.
For such reason, Aluminium scrap, in general, is somehow considered as “the bank of energy” which includes, more than forty (40) different typologies, as per the classification of Institute of Scrap Recycling Industries (ISRI).
Just to name some of them:
- Sheets and Foils
- Used Beverage Cans [UBCs]
- Wires and Cables
- Pistons and Motors Castings
- Extruded Profiles
- Borings and Turnings
- Dross, Skimming and Similar.
The composition of the slag and the aluminium compounds contained in it can heavily address the process design. Engitec has developed a process, based on hydrometallurgy, for the treatment of this slag that has been called STE (standing for Slag Treatment Engitec).
The Engitec proprietary technology for the secondary aluminum industry is the STE process is suitable for large or for small productions and can be installed directly at the aluminum recyclers’ site.
The STE process allows the recovery of both residual aluminum and of the salt fractions, which is re-used in the smelting process. The fine clean oxides in the slag are recovered for use in other industrial applications such as cement manufacturing.
All polluting gases generated during the aluminum salt slag leaching are combusted and the heat generated is used for water evaporation and salt crystallization. No liquid effluents are released from the plant and the gaseous emissions are kept within regulatory limits.
As of now, Engitec has sold and commissioned seven STE complete Plants of various capacity in Europe and Canada.
The Engitec
SPL Process
Aluminum is a particularly versatile non-ferrous metal. Its characteristics, in fact, make it one of the materials that will be used most in the energy transition. It is no coincidence that it was included, together with bauxite, in the list of critical raw materials drawn up by the European Commission and which concerns raw materials of extreme importance for the European economy, whose availability for the European industry could be put at risk.
Aluminum is produced through an electrolysis process, in which electricity is used to extract the metal from alumina (aluminium oxide- Al2O3), which in turn comes from bauxite (aluminium ore). The production process of primary aluminum is particularly energy-intensive, making the price of the metal strongly influenced by the cost of electricity, as well as the cost of alumina. According to the most reliable statistics, the production of primary aluminium in 2022 was in the range of 70 million tons on worldwide basis.
One of the valuable wastes resulting from the process of production of Aluminium is the so-called Spent Pot Liner (SPL) Engitec has developed an innovative process for the treatment of SPL based on hydrometallurgical technology.
By means of this process SPL is converted into valuable substances without generating any new residues or environmental issues (like water/air pollution, landfill issues etc.) ensures a final solution for all liabilities associated with these residues.
The innovative approach to the treatment of dross, SPL is to see it as a process to produce valuable products and not as a waste disposal process.
In the long term such a process needs to generate profits without the need for treatment fees being paid by the primary aluminum industry.
The integrated plant will maximize synergies, primarily avoiding the shipment of hazardous materials around the country and avoiding unnecessary logistics cost for the transport of dross, aluminum, salt slag and SPL to different treatment facilities. At the time being – May 2024 – Engitec is currently starting up a pilot plant in China.
SPL industrial plants are available for covering the needs of the largest smelter currently operating in Middle East and in China exceeding 1 million ton of aluminium per year.
Aluminum is produced through an electrolysis process, in which electricity is used to extract the metal from alumina (aluminium oxide- Al2O3), which in turn comes from bauxite (aluminium ore). The production process of primary aluminum is particularly energy-intensive, making the price of the metal strongly influenced by the cost of electricity, as well as the cost of alumina. According to the most reliable statistics, the production of primary aluminium in 2022 was in the range of 70 million tons on worldwide basis.
One of the valuable wastes resulting from the process of production of Aluminium is the so-called Spent Pot Liner (SPL) Engitec has developed an innovative process for the treatment of SPL based on hydrometallurgical technology.
By means of this process SPL is converted into valuable substances without generating any new residues or environmental issues (like water/air pollution, landfill issues etc.) ensures a final solution for all liabilities associated with these residues.
The innovative approach to the treatment of dross, SPL is to see it as a process to produce valuable products and not as a waste disposal process.
In the long term such a process needs to generate profits without the need for treatment fees being paid by the primary aluminum industry.
The integrated plant will maximize synergies, primarily avoiding the shipment of hazardous materials around the country and avoiding unnecessary logistics cost for the transport of dross, aluminum, salt slag and SPL to different treatment facilities. At the time being – May 2024 – Engitec is currently starting up a pilot plant in China.
SPL industrial plants are available for covering the needs of the largest smelter currently operating in Middle East and in China exceeding 1 million ton of aluminium per year.
